Yemen, one of the Arab world’s poorest countries, has been devastated by a civil war. Here we explain what is fuelling the fighting, and who is involved.
How did the war start?
The conflict has its roots in the failure of a political process supposed to bring stability to Yemen following an uprising in 2011 that forced its long-time authoritarian president, Ali Abdullah Saleh, to hand over power to his deputy, Abdrabbuh Mansour Hadi.
As president, Mr Hadi struggled to deal with a variety of problems, including attacks by jihadists, a separatist movement in the south, the continuing loyalty of security personnel to Saleh, as well as corruption, unemployment and food insecurity.
The Houthi movement – known formally as Ansar Allah (Partisans of God) – took advantage of the new president’s weakness.
The Houthis, who champion Yemen’s Zaidi Shia Muslim minority and fought a series of rebellions against Saleh during the previous decade, seized control of their northern heartland of Saada province in early 2014 and then began advancing southwards.
Disillusioned with the transition, many ordinary Yemenis – including Sunnis – supported them, and in late 2014 and early 2015 the rebels gradually took over the capital, Sanaa.
The Houthis and security forces loyal to Saleh – who was thought to have backed his one-time enemies in a bid to regain power – then attempted to take control of the entire country, forcing Mr Hadi to flee abroad in March 2015.
Alarmed by the rise of a group they believed to be backed militarily by regional Shia power and rival Iran, Saudi Arabia and eight other mostly Sunni Arab states began an air campaign aimed at defeating the Houthis, ending Iranian influence in Yemen and restoring Mr Hadi’s government.
The coalition received logistical and intelligence support from the US, UK and France.